Finisher for laying and tamping bituminous conglomerates over road pavings



y 1952 c. DOMENIGHETTI 3,035,499

FINISHER FOR LAYING AND TAMPING BITUMINOUS CONGLOMERATES OVER ROAD PAVINGS Filed March 7. 1955 2 Sheets-Sheet l y 1962 c. DOMENIGHETTI 3,035,499-

FINISHER FOR LAYING AND TAMPING BITUMINOUS CONGLOMERATES OVER ROAD PAVINGS Filed March 7. 1955 2 Sheets-Sheet 2 United States Patent )fitice 3,035,499 Patented May 22, 1962 3,035,49 FINISHER FOR LAYING AND TAMPING BITUMI- NOUS CONGLOMERATES OVER ROAD PAVINGS Costante Domenighetti, Piazzale Giulio Cesare 20, Milan, Italy Filed Mar. 7, 1955, Ser. No. 492,334 Claims priority, application Italy Mar. 13, 1954 Claims. (Cl. 9446) The present invention relates to machines for laying and tamping bituminous conglomerates over road pavings. More particularly the present invention is concerned with a machine to form a smooth and compact mat having a predetermined cross section.

In accordance with the invention, a machine comprises the combination of three groups of units assembled together, but separable. The first group comprises a frame formed by two longitudinal side slides bearing upon the ground and carrying two or more cross vibrating blades, the second comprises a crawler type tractor whose tread is such as to permit its entering between the fore portions of said slides, and the third comprises a hopper connectable with one of the two preceding groups and provided with a wall having its lower end adjustable in height.

An object of the present invention is to provide a machine which lays thin conglomerate mats of the order of about mm. It has been observed through experience that a stilt metal blade does not easily ride over irregularities. Actual trials have revealed that a substantial advantage is gained by replacing the still blade or a portion of it with a rubber blade, interchangeable with the still metal blade, so that it will be possible, as a result of a quick substitution, to carry out work previously deemed almost impossible.

It was found, during the operation of laying machines, that the so called coarse first adjustment of the hopper, when it was a question of laying very limited quantities of material, was not sufliciently close and exact. It was found expedient to so arrange closure plates for the hopper outlet, which plates may also be disposed alternately, so as to let the material fall in the form of longitudinal strips instead of a continuous and uniform mat or layer. The closure plates have lower extensions guiding the material until the material is almost in contact with the road.

Lastly, in order to reduce the width of the mat to be laid a supporting cross piece has been provided, carrying vertical and longitudinally disposed walls or partitions touching the ground and confining the material laterally.

In order to reduce the overall dimensions of the finisher while still leaving it almost entirely assembled, it has been considered, according to the present invention, to render the fore and side walls of the hopper swingable, so that they may be folded upwards and side ways for transportation, thus permitting a reduction in the width of the machine by the amount necessary to make it capable of travel upon roads, and to mount upon a single truck the whole machine, without having to disassemble it.

The annexed drawings schematically show by way of example the various embodiments of the invention.

FIG. 1 shows a perspective view separately and very diagrammatically of the three groups constituting the major portions of the machine according to the invention, wherein for the sake of clarity all details pertaining to the blades have been omitted;

FIG. 2 shows in a longitudinal section a diagram of the machine operation;

FIG. 3 represents in a vertical section and on an enlarged scale a vertical section of a vibrating blade for the structure of FIG. 1;

FIG. 4 is a plan view of the assembled machine, i.e.

with the three groups inserted into each other for operation;

FIG. 5 is a side view of a modified construction;

FIG. 6 is a plan view of the structure of FIG. 5; and

FIG. 7 is a partial perspective view illustrating additional side parts completing and adjustably extending the vibrating blade.

The vibro-finisher of the invention for bituminous conglomerate road mats comprises three groups ABC (FIG. 1), which in operating condition are rigidly connected (FIG. 4) to form a single unit and partly fit into each other in a predetermined relationship which constitutes a characteristic feature of the invention and provides for an optimum distribution of the conglomerate.

In FIG. 1, the groups are shown in perspective view very diagrammatically and set apart from each other in order to indicate each ones functions better. It should be understood that for the sake of clarity all the constructive details of the machine have been purposely omitted and that the purpose of FIG. 1 is merely to show the main function of the three groups.

Group A consists of two slides 1 interconnected by a strong frame 14 upon which are transversely mounted the two vibrating blades 2. In this representation of group A, the vibrating means is omitted. The position of the blades is adjustable by means of handwheels 3 which act upon screws 13 (FIG. 3), which screws are three in number. Two of these screws are arranged at the outer ends of the blades and one of thescrews is between the inner ends of the blades 2, thus permitting a variation in the road profile according to the diiferent requirements of the road surfaces. The function of slides 1 is to support blades 2, and to maintain them at the right level.

A preferred Way for setting the blades 2 into vibration and adjusting their position is represented in FIG. 3 and will be discussed subsequently.

It will be appreciated that the three adjusting screws 13 can be operated simultaneously so as to cause the blades 2 to lift or lower together, or else they can be singly actuated or two of the blades can be actuated together, so as to cause the lower or outer edge of the blades to assume relatively different positions. This provides for the laying of the bitmuminous conglomerate in the form of a crown, a V or a flat horizontal surface. It should be understood that the screws 13 are adjusted in advance, for instance, before starting the laying of conglomerate on a curve or turn where, as it is known, the outer portion must be higher than the inner portion to obtain the proper banking of the roadway. This adjustment is carried out only where it is necessary to vary the shape of the roadway in accordance with requirements. When the blades 2 are vertically vibrated, the material deposited between the tracks 4 is spread out, tamped and is at the same time struck oif at the desired height which is set by means of the adjusting screws 13. As the slides 1 bear on the road base, and not on the deposited conglomerate, it will be clear that this adjustment by means of screws 13 is very accurate.

The slides 1 are made of two pieces which are hinged together by means of a vertical hinge 23 so as to present a tail 1 which can be swung to one side. During operation, tail 1 is kept in an aligned position with the other portion 1 by means of diagonal tie rods 22. The articulation or vertical hinge 23 allows the swinging of the tails 1 against the portions 1 after the diagonal tie rods 22 are freed in order to reduce the length of the slides during transportation. The conglomerate which is deposited between the tracks is spread out by the operation of blades 2.

The length of the slides 1 when lengthened with the tails 1 is such that the blade is not affected in the least by the undulations or irregularities of the road base in the longitudinal direction. In practice, the complete length is about 2.50 to 2.80 meters.

This system of finishing and striking off, by means of transverse vibrating blades mounted upon long longitudinal slides bearing upon the ground, fulfills the most modern concepts and constitutes an improvement and an advantageous feature with respect to other known machines, the height of the blades being referred to the prelaid conglomerate and not to the slide bearing plane in the known machines. In the known machines it often happens that during the striking ofi of the vibrating blade, noticeable resonance oscillations are set up which are due to the summing up of undulations of the road base.

FIG. 3 shows a practical way in which the vibrating blades can be mounted on the machine and in particular on group A.

The vibration is transmitted to the blades 2 by means of eccentrics 9 which are driven by the main engine through conventional transmission means and gear reducing box 16 (FIG. 1) coupled after the group B has been connected with group A by means of bolts or pins 17 and connecting rods 18. The upper or supporting part 24 of the blades 2 is connected with the corresponding eccentric 9, which rotates to displace the blade, while the lower part 2 which is the blade proper is formed from a stronger material and is replaceable (FIG. 3). Briefly, the support 24 for the blade and the blade [2 itself will be hereinafter referred to as a'blade 2-24. Blades 2-24 are mounted on the frame 25 so as to be adjustable in height, and are retained against the frame 25 by means of springs 26 anchored on pin 27 to the stationary frame 14. Said frame 14 is rigidly connected to slides 1 and to handwheel 3 which actuates screw 13 for lifting and lowering the frame 25 carrying the corresponding blade 2-24. The two blades 2-24 are so constructed as to be inclinable one with respect to the other and alternatively with respect to the ground. The cross piece 28 fixed to the movable frame 25 serves as a guide and support for the lower part of the blades 2-24 during their vibratory displacement. During vibration, the lower end of the blade 2-24 describes an ellipse. As experimentally ascertained, this permits a very good tamping of the material.

The group B can be called a guide and traction group and is similar to a Caterpillar crawler tractor. In this group are two sturdy tracks 4, engine 5, preferably a diesel engine, a box 16 containing the reduction gears, a speed box, clutches etc., from which extend the steering control levers 6 and the gear box control lever 10. This group B with all its accessories constitutes the guide and traction group of the machine, which is shown in FIGS. and 6 too, wherein to simplify the figures the crawlers and connecting cross rod 32 of the groups are only diagrammatically shown. The bottom of the group B is elevated from the ground so as to permit the passage of conglomerate therebeneath.

The width of slides 1 is almost the same as that of the crawlers 4. In working position, the group B is longitudinally inserted between the front half portion of the slides 1 and occupies the entire distance therebetween. Group B is connected to the group A by means of bolt holes 17 (or 17') fixed to the side of the frame of group B and entering a hole 18' of the fore end of the connecting rod 18, which can accomplish a limited oscillation around the pin 19 as a result of the provision of a large opening 20 on each slide 1. The second bolt hole 17 is provided for varying the distance betwen groups A and B during the assembling.

The group C consists of a large hopper '11 into which normal dumping trucks can completely discharge while those of a greater capacity can discharge in two operations. The hopper may be very easily and rapidly engaged and disengaged from the truck and therefore provides for an enormous saving of labor. As clearly shown in the figures, the width of the inlet opening of the hopper 11 is the same as the width of the bottom or outlet open= ing of the same and is not funnel-shaped as in the conventional machines of this type, which therefore require conveying screws to spread out the material to the sides. F urthermore, the width of the hopper 11 is almost the same as that of the tracks or crawlers 4 so that, when in working position, the whole group C may be longitudinally inserted between the front half portion of the crawlers 4 occupying the whole distance therebetween. Group C is connected to group B by links 11a. The conglomerate falling from the bottom of the hopper spreads out by itself between the tracks or crawlers 4 and the crawlers between the slides 1 after which it is tamped by the vibrating blades 2-24. As a result of the particular relative position of the three groups, one with respect to the other, the machine according to the invention is extremely simple, reliable and inexpensive.

The hopper 11 is provided with apertures the discharge from which is controlled by shutters or blades 7, arranged at the rear or downstream wall of the hopper, the blades 7 being actuated by adjusting screws 8 and handwheels 12 and striking off the discharged material at selected height.

Hese blades 7 are provided to regulate the discharge of the material from the hopper 11, so as to present in front of the vibrating blades 2-24 of the group A the proper or correct quantity of conglomerate to be deposited, struck off, vibrated, tamped and then smoothed out in order to make a perfect mat. The vibrating blades 2-24 may be heated at their rear portion in any conventional manner.

The schematic operation of the vibrating finisher is represented in FIG. 2 of the drawing,-in which the arrow '29 shows the forward direction of running of the machine. It will be appreciated that the blades 7 of the hopper 11, controlled through the adjusting screws 8 and handwheels -12, exactly regulate the quantity of material deposited in front of the vibrating blades 2, whose height is in turn adjusted with great precision by means of the screws 13 and handwheels 3 acting upon the blades.

It is important to note the manner in which the adjusting of the blades 7 by means of the screws 8 permits the vibrating blades 2-24 to operate, while having in front of them the exact quantity of material necessary for obtaining a very good laying of the mat.

The vibrating motion of the blades 2 further acts in such a manner not only as to realize the striking off but also a tamping of the material, which is very important when the subgrade irregularities are noticeable, in which case a simple striking ofl would lead to the formation of subsequent undulations over the upper mat surface due to the compression exerted by the road rollers and by trafiic.

This machine may be very easily transported on the road. The hopper 11 is disconnected while the two groups A and B remain connected to each other. The tails 1' of the slides 1 are swung around about the hinges 23 to the sides in order to reduce the length of the two groups which are then mounted on a truck and transported in a direction perpendicular to the operating direction of the finisher. The two groups A and B, when connected together, reduce the length of these two groups as mentioned above, and both may be included in a carriage gauge templet (2.50 m.) as required by some road codes. Group C, which is constituted by the hopper 11, is also mounted on a truck frame and towed either by a separate vehicle or by the same vehicle transporting groups A and B.

It has been found possible to obtain a better surface distribution of the conglomerate by adopting a vibrating blade 2-24 whose extreme portion 2 is formed of a flexible and yieldable material, such as, for instance rubber. To increase the width of the conglomerate additional blades 30 may further be added, which are detachably mounted at the sides of the machine (FIG. 6, and in more detail in FIG. 7). These side blades 36- are shaped in the form of a sharp elbow and are fixed by conventional pivot 47 with a certain inclination with respect to the main blade 224, to the end of deviating a portion of the material or conglomerate coming out of the hopper and carrying it to the exterior of the slides 1 toward the elbow shaped end 30. At end 30' the material or conglomerate collects in a heap 45 (FIG. 6) which, passing under the blade 30 which is slightly elevated from the ground distributes itself over the ground in a supplementary strip 46 widening the surface of the mat. The blades 30, instead of being fixed, may be displaceable about vertical pin 47. With this arrangement the width of the supplementary strip 46 may be varied at will.

In another embodiment of the invention, the supplementary blades 30 may be pivoted or welded at the point 52 to the end of the vibrating blade 224 and participate to its vibratory movement. Besides, the blades 30 may also have at their lower ends a rubber portion, as provided for the main blade 224.

Vertical longitudinal walls or partitions 21 may be displaceably and removably mounted upon a supporting cross piece 32 by means of slidable brackets or hooks or sleeves 31 adjustable with respect to the hopper 11, in order to confine the conglomerate laterally, thus limiting the laying within a predetermined width. Horizontal plates 33 wedged in hopper 11 have also been provided, operating as partial covers and disposed over the outlet opening of the hopper 11, for limiting the area of passage of the material as required.

In order to facilitate the transportation of the machine on the road, provision has been made to render the walls of the hopper 11 swingable, so as not eo exceed the maximum overall dimensions allowed by the road code. To this end, the fore part of the side walls 34, of the hopper 11, ie the part which projects to the front of the machine outside of the crawlers 4, is vertically hinged at vertical hinges 36 to the back part of the side walls 34. The back part of the side wall together with the vertical back cross wall or end wall of the hopper are fixed to each other and are usually supported by the crawlers frame of the group B in any conventional manner. The inclined forecross wall 35 of the hopper is horizontally hinged at hinge 37 so as to be swingable upwards in the direction of arrow 40 (FIG. by means of a rope 39 actuated by a handwheel 38. Once the inclined fore-cross wall 35 has been lifted upwards, the fore part of the side Walls 34 may be swung inside about the vertical hinges 36 so that all of the parts of the hopper projecting out of the crawlers are folded in so as to reduce the overall dimensions of the machine.

If, as shown in FIG. 6, a truck 41 approaches on the ide to load the hopper, the hopper can be swung for instance about a pivot 42 (see dotted lines, hopper 11) allowing a 90 rotation in the direction of the arrow 43 (FIG. 6) to get the hopper under the discharge opening of the truck 41 which is no longer in front but at the side of the machine.

During the rotation, the hopper is entirely supported on one side by the pivot 42 and is also supported at the opposite side by either a wheel 44 or a derrick system. During this rotation, of course, the hopper must be entirely closed at the bottom with cover plates or shutters 33, which are removable from the outside, either by hand or mechanical means, and the hopper is swung back to the working place.

The machine according to the invention is of a simple and strong construction as a result of the particular relative position of its three units A, B and C, an optimum distribution and tamping of the conglomerate is provided with the least possible and least expensive means. The machine therefore ofiers all of the advantages of more complex and more delicate and higher priced machines used up to the present for the same work without presenting, however, the disadvantages of requiring expensive maintenance and the possibilities of break-down of the delicate parts.

\Vhat I claim is:

1. Apparatus comprising: a slide unit, a guide and traction unit having a determinable forward direction of travel, and a hopper unit, said slide unit comprising spaced slides, a frame connecting said slides, and vibrating blades adjustably supported by said frame and arranged transversely of said slides, said slides including hingeably connected rear extremities, said guide and trac tion unit comprising an engine, crawlers coupled to said engine and driven thereby, said crawlers being in spaced parallel relation and extending between said slides in juxtaposition thereto, said hopper unit extending between said crawlers and defining an outlet opening extending therebetween, said hopper unit comprising a blade operatively disposed at the rear of said opening to control the height of substance discharged therethrough, means to control the height of said blade, and means for coupling said hopper and slide units to said guide and traction unit.

2. Apparatus as claimed in claim 1 comprising cover plates in said hopper unit for selectively covering said outlet opening to confine the discharge therefrom.

3. Apparatus as claimed in claim 1 comprising adjustment means in said slide unit for adjusting the transverse inclination of the blades in the latter said unit to control the contour of substances deposited.

4. Apparatus as claimed in claim 1, wherein said slides are provided with lateral openings, and auxiliary blades extending through said openings and pivotally connected on a vertical axis to said slides.

5. Apparatus as claimed in claim 1 comprising detachable flexible members on the bottom edges of said blades in said slide unit.

References Cited in the file of this patent UNITED STATES PATENTS 1,532,841 Stayton et al Apr. 7, 1925 1,979,619 Hemstreet Nov. 6, 1934 1,987,398 Gardiner -1 Jan. 8, 1935 1,994,437 Reis Mar. 12, 1935 2,054,436 Mosel Sept. 15, 1936 2,109,020 Abernathy Feb. 22, 1938 2,116,468 Cost May 3, 1938 2,185,645 Mosel Jan. 2, 1940 2,225,481 Lundbye Dec. 17, 1940 2,252,717 Lundbye Aug. 19, 1941 2,289,168 Barber July 7, 1942 2,295,519 Millikin Sept. '8, 1942 2,303,486 McConnaughay Dec. 1, 1942 2,351,592 Barber June 20, 1944 2,380,435 Heltzel July 31, 1945 2,473,961 Mandt et al. June 21, 1949' 2,586,396 Trampler Feb. 19, 1952 2,757,587 Mentes Aug. 7, 1956 FOREIGN PATENTS 240,544 Great Britain Oct. 2, 1925 21,696 Norway Apr. 15, 1930 

